<p>I figured that they would rather not read additional material, but I've written a quick analysis of my grades to explain why they were bad (~500 words). I did this because I was trying to keep my SOP and PS positive and remain confident in my abilities. I also figured that this document was also a good way to show them I'm really analysis oriented.</p>
<p>My grades are bad so this would definitely help me, but I'm unsure as to whether or not the fact that it is an additional document would hurt me (although they have a seperate section to upload additional documents).</p>
<p>If they didn't want additional documents, they wouldn't have a spot for them. They want anything that can help them get a true picture of you as a candidate. It sounds like the document you mention does just this.</p>
<p>I think some schools ask applicants not to send extra documents because of the huge numbers of applications they receive. You might find this kind of information in the schools' FAQ or in other parts of their web sites. So, I think it would be better to check if they explicitly mention this matter on their web sites before you send additional documents.</p>